The invention relates to polymeric hose of the rubber or plastic type with distinct metal reinforcement, but more particularly, the invention applies to automotive type heater hose with embedded wire reinforcement as a means for giving the hose shape retentivity.
Engine compartments appear cluttered following a trend for small cars and additional engine components required to meet exhaust emission standards. Several original equipment manufacturers require molding heater hoses and exhaust emission hoses to a particular serpentine shape for component packaging where heretofore, such hoses could be freely shaped from lengths cut from reels of bulk hose. The trend for molding hoses molded to several different shapes makes it difficult or expensive for aftermarket suppliers to stock all hoses necessary to fit all applications.
Heater hoses usually have an inside diameter ranging from about 0.5 to about 1 inch. Reformable inserts for such hoses have been proposed but such inserts introduce several drawbacks. The inserts, by definition, introduce some blockage into the hose bore which, in the case of the smaller hoses, is unsatisfactory. Also, the reformable inserts do not solve the problems of the aftermarket supplier because each reformable insert must be designed for a hose of specific length. Thus, such a solution to shape retentive hose prevents an aftermarket supplier to cut random lengths of hose from a reel or it prevents a user from cutting a piece of aftermarket supplied hose to a shorter, more desirable length. An example of a formable insert for hose appears in U.S. Pat. No. 4,327,775.
In avoiding the fixed lengths and bore obstruction problems of hoses with reformable inserts disposed in a hose bore, one prior art hose construction uses a helical wire embedded in a hose cover. The wire has a diameter less than the cover thickness so it does not interfere when the hose is coupled to a nipple with a circumferential type hose clamp. While such hose has collapse resistance when bent to a small bend radius, it does not have shape retentivity.